REFLECTOR: seal bulkheads before baffles?

[Jim Agnew]

I sealed the strakes with Jefco (top and bottom) first then sanded for the baffles which were glassed to the lower strake.  The baffles then were coated with Jefco and the upper strake was installed, not a single leak.
 
Jim

 
James F. Agnew
Jim_Agnew_2 at Yahoo.Com
Tampa, FL
Velocity 173 Elite Aircraft Completed & Flying 



----- Original Message ----
From: John Tvedte <johnt at comp-sol.com>
To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
Sent: Thursday, August 2, 2007 1:30:43 PM
Subject: Re: REFLECTOR: seal bulkheads before baffles?


TEC,

Well - I'd have to re-read the manual - but when we sealed our strakes, the baffles were treated just like they were bulkheads - yes, we glassed the mouse holes, and made sure they didn't have any pinholes.  That meant digging some of the foam out- and filling with epoxy/micro - and then glassing.  If you have a pin hole on a bulkhead - it would allow fuel to migrate into the foam as well.  

Strakes are one of the most critical construction areas of the Velocity - methods have changed somewhat over the years - i.e. Jeffco - also it is suggested to seal the strakes when closing with Jeffco - that means use Jeffco to glue the top of the strake on - 'gray goo' Aeropoxy is used on the strake to spar area - and outside the tank sealing area on the leading edge.

On the pre-seal - what we did is used a lightweight bid - and covered the entire fuel area of the strake - in our case, 3 of the strakes were made without peel ply - so had very rough surface -and pinholes.  We had to grind the stitching and sand them to get a 'bite' - and then put the lightweight bid and peel ply on.  So - that is what we did to seal the strakes properly.

________________________________

From: reflector-bounces at tvbf.org on behalf of HYTEC45 at aol.com
Sent: Thu 8/2/2007 11:34 AM
To: reflector at tvbf.org
Subject: Re: REFLECTOR: seal bulkheads before baffles?


In a message dated 8/2/2007 7:05:02 A.M. Pacific Standard Time, bdtopp at comcast.net writes:

    
    TEC,
       I don't believe anybody is sealing the portion of the strake that is directly under a bulkhead or baffle.  I know I didn't.  In theory, fuel should never see that area if you have a really good coat of Jeffco on everything including a nice bead on the top of the baffles and bulkheads when closing out the strake.
     
    Bruce

Bruce,

I also did not pre-seal below the baffles prior to installation, and have not had any leaks in 11 years.  However, I have always worried about it, and wish I did.  A bulkhead and a baffle are two different things (unless things have changes in the plans).  A bulkhead's core will never see fuel as it is stopped by it's inner skin, where a baffle's inner foam core will see fuel(unless things have changed and all edges including the mouse holes are tapped and sealed), and can migrate through it to the surface, approximately 9/16" wide, area of the inner strake skin the baffle is sitting on.  While the perimeter and face of a bulkhead can be sealed as it's exposed, the area of the strake skin the baffle is sitting on cannot.  I worried after I closed my strakes about this, and just lucked out that there were no pin holes in the factories lay ups.  I like the pre-seal with peal ply before installing the baffles.  Wish I did.  If you have put fuel in with no
 leaks, we both should go to Vegas.
TEC



________________________________

Get a sneak peek of the all-new AOL.com <http://discover.aol.com/memed/aolcom30tour/?ncid=AOLAOF00020000000982> .
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.tvbf.org/mailman/private/reflector/attachments/20070802/76010a74/attachment-0001.htm